It is required that patients in hospitals and convalescent homes and residents of multi-unit housing for the elderly have a call system with which to call for assistance or emergency help from nurses or attendants. Many such call systems utilize a pull-cord station. A pull-cord station consists of a wall-mounted switch with a cord connected to it which hangs to the floor. Pulling the cord activates the switch and its associated alarm circuitry.
Persons are only protected by such a pull-cord station if they are within reach of a pull-cord or are able to get to one. Accidents can occur anywhere and are often immobilizing. Therefore, it may be difficult or impossible for a person to reach a pull-cord quickly or at all in an emergency if, for example, he or she is in another room and/or is unable to move.
The remote control for pull-cords to be described here is intended to enable a person to activate a pull-cord station by wireless remote control from anywhere in the living area. No pull-cord stations up until now have had a remote control capability. Therefore, providing essential, wide area protection in care facilities with pull-cord stations has required extensive reconstruction of the alarm circuit.
U.S. Pat. No. 4,605,927 discloses a controller responsive to an FM transmitter which must be hard-wired into a call-system. U.S. Pat. No. 3,971,028 discloses a radio responsive rachet relay which would require hard-wiring if applied to a call system. U.S. Pat. No. 4,418,334 discloses a call system with no remote control capability. U.S. Pat. No. 3,827,039 discloses a portable alarm utilizing a pull-cord but which is too large to constantly carry and which is lacking in signal transmitting features required of a hospital call system. U.S. Pat. No. 4,355,309 discloses a digitally encoded transmitter which controls a relay circuit that would require hard-wiring if applied to a call system. U.S. Pat. No. 4,298,863 discloses a call system that has no remote control and which activates electrical contacts that must be hard-wired to an existing call system.
Other easily portable distress signalling devices are available which emit a loud alarm signal. These devices do not communicate directly with the proper personnel and cause a major local disturbance. Other aid summoning systems consist of remote controlled dialing machines that deliver a digital message over telephone lines. Such systems must be hard-wired to an existing call system. These systems also depend upon unreliable telephone lines and require expensive digital message receiving equipment and staff training.
No device has been available until now to easily and inexpensively convert a pull-cord station to a remotely controllable, broad protection, call system.